diff --git a/.env.example b/.env.example
index 591ecb63..9890a24c 100644
--- a/.env.example
+++ b/.env.example
@@ -3,6 +3,12 @@ JWT_SECRET="<generate with: openssl rand -base64 32>"
 POSTGRES_URL="postgres://postgres:password@localhost:5432/officer"
 MAIL_TRANSPORT="smtp://localhost:1025"
 PUBLIC_URL=http://localhost:9000
+
+# Guards (CORS origin checks, rate limits, password-strength rules) are ON unless this is set to
+# "dev" or "development". Leave it unset or set it to "production" for a real deployment; only set
+# it to "dev" on a local machine you trust, since that disables all three.
+PUBLIC_BUILD_ENV=production
+
 DATA_PATH=/path/to/data
 OFFICER_ITEMS_DIR=/path/to/officer-items
 HOME_DIR=/home/user
diff --git a/src/servers/_middlewares/origin-validation.ts b/src/servers/_middlewares/origin-validation.ts
index 025def78..65fcfcb7 100644
--- a/src/servers/_middlewares/origin-validation.ts
+++ b/src/servers/_middlewares/origin-validation.ts
@@ -1,7 +1,8 @@
 import type { MiddlewareHandler } from 'hono';
 import * as errors from '../custom-errors';
+import { IS_DEV_BUILD } from '../build-env';
 
-const { PUBLIC_BUILD_ENV, PUBLIC_URL, EXPO_PUBLIC_CLIENT_ORIGIN } = process.env;
+const { PUBLIC_URL, EXPO_PUBLIC_CLIENT_ORIGIN } = process.env;
 
 // The allowed production web origin comes from PUBLIC_URL in .env (e.g. https://officer.pastilhas.dev),
 // not a hardcoded domain.
@@ -13,9 +14,7 @@ const PUBLIC_ORIGIN = (() => {
   }
 })();
 
-const WEB_ORIGINS: Record<string, string[]> = {
-  production: PUBLIC_ORIGIN ? [PUBLIC_ORIGIN] : [],
-};
+const WEB_ORIGINS: string[] = PUBLIC_ORIGIN ? [PUBLIC_ORIGIN] : [];
 
 const CHROME_EXTENSIONS: string[] = [
   // 'chrome-extension://<id>'
@@ -27,9 +26,7 @@ const APP_ORIGINS: string[] = [
 ].filter((o): o is string => Boolean(o));
 
 export function isOriginAllowed(origin: string | undefined, host?: string): boolean {
-  if (!PUBLIC_BUILD_ENV || PUBLIC_BUILD_ENV === 'dev' || PUBLIC_BUILD_ENV === 'development') {
-    return true;
-  }
+  if (IS_DEV_BUILD) return true;
 
   if (origin) {
     if (origin.startsWith('chrome-extension://')) {
@@ -40,13 +37,11 @@ export function isOriginAllowed(origin: string | undefined, host?: string): bool
       return true;
     }
 
-    const allowed = WEB_ORIGINS[PUBLIC_BUILD_ENV];
-    return !!allowed?.includes(origin);
+    return WEB_ORIGINS.includes(origin);
   }
 
   if (host) {
-    const allowed = WEB_ORIGINS[PUBLIC_BUILD_ENV];
-    return !!allowed?.some((o) => o.endsWith(host));
+    return WEB_ORIGINS.some((o) => o.endsWith(host));
   }
 
   return false;
diff --git a/src/servers/_middlewares/rate-limiter.ts b/src/servers/_middlewares/rate-limiter.ts
index e87136e5..75a8a3a0 100644
--- a/src/servers/_middlewares/rate-limiter.ts
+++ b/src/servers/_middlewares/rate-limiter.ts
@@ -1,5 +1,6 @@
 import type { Context, MiddlewareHandler } from 'hono';
 import * as errors from '../custom-errors';
+import { IS_DEV_BUILD } from '../build-env';
 
 type RateLimitEntry = {
   count: number;
@@ -24,9 +25,6 @@ function cleanupStore(store: Map<string, RateLimitEntry>) {
   }
 }
 
-const { PUBLIC_BUILD_ENV } = process.env;
-const isProduction = PUBLIC_BUILD_ENV === 'production' || PUBLIC_BUILD_ENV === 'staging';
-
 export function rateLimiter(options: RateLimiterOptions): MiddlewareHandler {
   const {
     windowMs,
@@ -43,7 +41,7 @@ export function rateLimiter(options: RateLimiterOptions): MiddlewareHandler {
   setInterval(() => cleanupStore(store), 60_000);
 
   return async (ctx, next) => {
-    if (!isProduction) return next();
+    if (IS_DEV_BUILD) return next();
 
     const key = keyGenerator(ctx);
     const now = Date.now();
diff --git a/src/servers/api/auth/change-password.ts b/src/servers/api/auth/change-password.ts
index d4dd9c64..ce221d55 100644
--- a/src/servers/api/auth/change-password.ts
+++ b/src/servers/api/auth/change-password.ts
@@ -4,13 +4,11 @@ import argon2 from 'argon2';
 import { sign } from '@@/jwt';
 import * as errors from '@@/custom-errors';
 import { validatePassword } from './validate-password';
-
-const { PUBLIC_BUILD_ENV } = process.env;
-const isProduction = PUBLIC_BUILD_ENV === 'production' || PUBLIC_BUILD_ENV === 'staging';
+import { IS_DEV_BUILD } from '@@/build-env';
 
 export const changePasswordHandler: Handler = async function (ctx) {
   const { password, newPassword } = ctx.get('body');
-  if (isProduction) validatePassword(newPassword);
+  if (!IS_DEV_BUILD) validatePassword(newPassword);
   const reqUser = ctx.get('user');
 
   const dbUser = await getUserById(reqUser.id);
diff --git a/src/servers/build-env.ts b/src/servers/build-env.ts
new file mode 100644
index 00000000..1af662bf
--- /dev/null
+++ b/src/servers/build-env.ts
@@ -0,0 +1,6 @@
+// Officer relaxes its guards (origin checks, rate limits, password rules) only when PUBLIC_BUILD_ENV
+// explicitly asks for it. Anything else — including an unset variable — gets the hardened path, so a
+// deployment that forgets to set it fails closed rather than silently opening up.
+const { PUBLIC_BUILD_ENV } = process.env;
+
+export const IS_DEV_BUILD = PUBLIC_BUILD_ENV === 'dev' || PUBLIC_BUILD_ENV === 'development';